[TASK] Move cursor::pointer to complete header area in IRRE

The whole header is clickable, thererfore move the css rule
to this place.

Change-Id: Ia864faba4976fc5e2e84299a42e2661a9566be1c
Resolves: #55611
Releases: 6.2, 6.1
Reviewed-on: https://review.typo3.org/27285
Reviewed-by: Stefan Neufeind
Tested-by: Stefan Neufeind